class Abc{
	public static void main(String[] args) {
int a=88;
    if(a>80 && a<=100){
    System.out.println("A");}
    else if(a>70 && a<=80){
    System.out.println("B");}
	else if(a>60 && a<=70){
	System.out.println("C");}
	else if(a>0 && a<=60){
	System.out.println("D");}
	}
}
